Silicone on sump spacer - tip of the day

[Romb 0]

Hello,

 

I have no idea why Peugeot thought it was a good idea to put only a gasket between the spacer and the sump and silicone between the block and the spacer. Silicone has a way of squeezing out when the surfaces mate and if that goo brakes loose in your sump there's a chance it will clog up the oil pick resulting in oil starvation and engine failure.

 

Anyhows, I do not often apply silicone so the amount was probably way too much, pic 1. Once I tightened the two hex screws to mount the spacer goo squeezed out. No problem as the sump was still off so just removed the excess silicone. But while tightening the sump afterwards a lot more goo came out on the outside, so probably on inside as well. I let it settle overnight and next day removed the sump and indeed a lot of goo all around the spacer edge, just waiting to fall into the oil pick up, pic 2 (it was more than on the pic). Very time consuming to remove, it's in hard to reach nooks and crannies.

 

Why they didn't simply go with a gasket is beyond me. Such a low cost item and the damage if it goes wrong can be critical, so from a cost-benefit analysis there doesn't seem to be a reason to use goo (unless it's because of materials, alu on alu or something, don't know about that).

 

I read that some fasten only the spacer first, let the silicone harden overnight and then apply the sump. Don't think that's a safe solution as the silicone may be somewhat harder, it's still maliable and when tightening the 20 or so sump bolts to 15ft-lbs I'm pretty sure it will squeeze out. All the bolts together press the spacer much tighter against the block then just the two spacer screws. So it settled in too loose a manner and will get squeezed out anyways when fitting the sump.

 

I guess the only way to make sure there's no goo in your sump is too mount the sump to torque, let it settle overnight and then remove the sump and start cleaning away. That is my tip of the day.

 

Bonus tip, once the spacer is fitted goo will also block the bolt holes. If you turn a bolt in and out much of it will stick to the top end allowing you to remove it before it hardens out.

Edited February 16, 2020 by Romb

[petert 588]

That is way too much silicone. Using silicone between the mating surfaces of both sump/spacer and spacer/block is factory correct. Fitting gaskets would leave the pump pickup too far away from the base of the sump. What ever you're using looks atrocious. The best sealant I've found for this application is ThreeBond 1211. You'll like it even better when time comes to remove it. Use just the thinnest of smears on BOTH surfaces.

 

The best procedure is to fit the spacer to block first, with the two cap screws and some spare M7 bolts/spacers/washers and torque to spec. You'll be able to see if any squeezes out. If it does, you've used too much. Leave for 24 hrs then fit the sump to spacer.

 

Trying to fit both at the same time will leave you bothered and flustered.

Edited February 17, 2020 by petert

[Romb 0]

Thanks, thats a very good tip on the spare bolts torqueing it temporarily. Why didn't I think of that :-)

 

The silicone should be good I hope, it's what BMW recommends for M engine valve covers, Drei Bond 1209

[Ozymandis 97]

Your using far too much goo.

[Romb 0]

15 hours ago, Ozymandis said:

Your using far too much goo.

Yes, my bad :-)

[Leslie green 111]

Handy tips for when I need to cheers 

[Tom Fenton 1,542]

Set the sump and then remove it? This is terrible advice. The silicone cures to both surfaces which provides the seal, if you then break that seal you are back to square one and it will leak. My "TIP OF THE DAY" - DO NOT DO IT LIKE THIS.

[Romb 0]

10 hours ago, Tom Fenton said:

Set the sump and then remove it? This is terrible advice. The silicone cures to both surfaces which provides the seal, if you then break that seal you are back to square one and it will leak. My "TIP OF THE DAY" - DO NOT DO IT LIKE THIS.

The sump has a gasket, only the spacer above it has silicone between it and the block.

 

Only bad thing of removing the sump is that the equal pressure of the bolts is removed so the spacer could hang a little in the middle, but that should be sub 0,5 mm or so, given that it's a thick piece of aluminum, the silicone hardened and there are also two spacer hex screws keeping it in place.

 

(this potential but probably marginal hanging you also have when first installing only the spacer and let it harden overnight, as the bolts need to come out then as well to fit the sump).

[Tom Fenton 1,542]

Sorry chap but I have done this job many times and you are talking rubbish. To have the front to call it the tip of the day is ridiculous. I’ll leave it up to everyone to decide for themselves.

[Romb 0]

1 hour ago, Tom Fenton said:

Sorry chap but I have done this job many times and you are talking rubbish. To have the front to call it the tip of the day is ridiculous. I’ll leave it up to everyone to decide for themselves.

I can't change the title, if you deem it misleading and needing change then please do as mod. My way may be stupid and I used way too much goo, but the tip referred more to the fact that excess goo for the amateur mechanic can really be a thing to watch out for. There are some threads were people question whether goo would seep in the pan and now there's some empirical evidence that it indeed does (if used too much), so that when in doubt it's worth to check and remove.

 

But what do you mean by breaking the seal ? Yes my way is convoluted, but as regards the silicone layer between block and spacer not different than Petert suggested above with first letting the spacer settle alone with temporary bolts and then remove them and place the sump. Only difference is that I didn't use helper bolts (which need to be shorter to clamp only the spacer to torque) but just used the sump with original bolts. Removing sump after settling to clear excess goo doesn't break a seal right ? There's still two hex screws leaving the spacer in place and between the sump and the spacer is a simple gasket, no silicone.

 

Please correct me if wrong, could be I'm overlooking something obvious.